High order DBR GaSb based single longitude mode diode lasers at 2 μm wavelength

Abstract

The GaSb-based distributed Bragg reflection (DBR) diode laser with 23rd-order gratings have been fabricated by conventional UV lithography and inductively coupled plasma (ICP) etching. The ICP etching conditions were optimized and the relationship among etching depth, duty ratio and side-mode suppression ratio (SMSR) was studied. The device with a ridge width of 100 μm, gratings period of 13 μm and etching depth of 1.55 μm as well as the duty ratio of 85% was fabricated, its maximum SMSR reached 22.52 dB with uncoated cavity facets under single longitudinal operation mode at room temperature.

Coupling Performance Enhancement of GaSb-Based Single-Transverse-Mode Lasers with Reduced Beam Divergence Obtained via near Field Modulation

“…The improved coupling power is especially favorable as the ideal candidate for direct or resonant pumping of the 2 µm fiber or solid-state laser hosts [2], which are currently seeded by light sources of 15-40 mW power level [21,22]. Moreover, the GaSb-based narrow waveguide scheme with optimized single-transverse-mode beam characteristics is also compatible with other laser devices that employ analogous epitaxial layers and waveguide structures, such as DFB, DBR, SOA, and SLD [23,24]. The optimized far-field beam profile and improved coupling performance enable the use of simple and low-cost standard optics for the collimation and focus of these devices while facilitating the promotion of extractable optical power for further utilization.…”

Promotion of Specific Single-Transverse-Mode Beam Characteristics for GaSb-Based Narrow Ridge Waveguide Lasers via Customized Parameter Design

“…The potential for higher output power with simultaneously good beam quality makes GaSb-based single-transverse-mode narrow ridge waveguide (RW) lasers ideally suited light sources for various scientific and commercial applications, such as pumping rare-earth-doped fiber amplifiers and solid-state lasers [ 8 – 10 ], seeding external cavity lasers [ 11 , 12 ], and nonlinear frequency conversion [ 13 ]. In addition, narrow RW structure is also widely employed in various laser devices, such as distributed-feedback (DFB) lasers [ 3 , 14 ], distributed Bragg reflector (DBR) lasers [ 15 , 16 ], superluminescent diodes (SLD) [ 5 , 17 ], semiconductor optical amplifiers (SOA) [ 18 ], and tapered lasers [ 19 ], owing to its ability to guarantee high transverse mode purity and stability, which enables the use of simple and low-cost optics for the focusing and coupling of these devices for further utilization.…”

“…In contrast, pumping or coupling applications put higher emphasis on the promotion of optical output power and the compression of beam divergence [ 10 , 18 , 19 ]. Meanwhile, GaSb-based DFB, DBR, or SLD devices require relatively deep ridge etching to obtain a more substantial coupling effect of the grating or curved structure with the active layer [ 3 , 15 , 16 ]. However, these distinctive and even competing demands were often neglected in previous research using GaSb-based single-transverse-mode laser diodes, in which a 5 -m width RW was usually adopted without systematic investigation [ 2 , 4 , 5 , 17 ].…”

High quality 2-μm GaSb-based optically pumped semiconductor disk laser grown by molecular beam epitaxy

“…Electromagnetic waves in this band have high spatial transmittance and high light source utilization rate. [1][2][3][4] Therefore, some applications can be served by optoelectronic devices operating in this band, such as environmental monitoring, free space communication, biotechnology, infrared radars, material processing, etc. [5][6][7] At present, a laser operating at 2 µm can be acquired by solid-state and fiber lasers doped with Tm 3+ and Ho 3+ and GaSb-based laser diodes.…”